There is a lot of talk about immigration right now. It is a teaching moment. Political candidates who want to be President are talking a lot of nonsense.

Start with the basic facts:

The U.S. is overpopulated and creates more ecological destruction per human than any other country on earth (yes, including China).

The economy can not be expanded infinitely.

There has been growing economic inequality.

Immigration amnesties lead to further illegal immigration.

Illegal immigrants mostly compete for the lowest paying jobs. Even legal immigrants tend to compete for entry level jobs, though some are wealthy or educated enough to join the upper class or upple middle class as soon as they get here.

Who else competes for the lowest paying jobs in America? High-school dropouts, and even graduates, of course. That means mainly children of people who themselves are marginally employed or work regularly, but for low wages. Working class and welfare class women. And, disproportionately, people who have traditionally been discriminated against, including African-Americans, American Indians, etc.

The people who advocate for immigration amnesty, and hence for unlimited future immigration to the U.S., are well-intended. They see it as a human rights issue.

And there are long-term benefits to immigration for the economy. More people means more demand and more workers, and so more GDP. Legalized immigrants can better match their talents to the job markets. That is why the Republican establishment used to lead in advocating for more immigration, including immigration amnesty. That is why the largest single amnesty was put in place in 1986 under President Ronald Reagan.

The immediate impact of new immigrants, whether legal or illegal, is pressure on those jobs that require little skill to perform. They are often hard jobs. This includes childcare, cleaning services, and unskilled physical labor. These are exactly the jobs that unskilled citizens, including poor white, black, and hispanic citizens also want. The competition for these jobs pushes down wages, often to below the official minimum wages. It makes finding full time work difficult, except perhaps during brief economic booms. It makes it even harder for families that have been in the United States for generations to accumulate the resources necessary to climb out of the bottom of the working class.

That is why labor unions, otherwise pretty liberal and supporters of the Democratic Party, have traditionally been for minimal immigration.

The effect on the U.S. and global environment is also negative. Most illegal immigrants come here because they are greedy and want to have a higher standard of living than they would have in their native nation. To the extent they achieve that they are using more energy and other natural resources. They are generating more greenhouse gasses, and they are speeding up global warming.

In an ideal world the idea that "all men are created equal" might mean that men and women could move freely, to live wherever they want. We don't live in an ideal world. We live on a dying earth where most nations are already populated beyond what is sustainable. That is particularly true of the United States.

What we really need is a one-child policy in the United States. Mexico needs a one-child policy. So does Canada. So does nearly every nation on earth.

So what is wrong with my dear liberal and leftist friends? They are mostly herd animals, and they are not much for thinking for themselves. They "buy" a package of positions on issues that make them feel good about themselves. They want an environmentalist merit badge and a human rights merit badge. On many issues those badges are quite compatible.

But not for immigration. Increasing immigration and anything that encourages illegal immigration are positions that have practical consquences. They help rich white employers and bankers. They hurt working class men and women, and disproportionately hurt black workers. And they hurt the environment.

Congress should change the immigration law to allow in a number of immigrants each year that will not have a negative impact on employment for unskilled citizens. Congress should not grant amnesty to illegal immigrants.